The legal requirement to download digital data from driver cards is every 28 days. For vehicle units it's every 90 days.

Those are the maximum periods.

Many operators download more frequently. Some do it just before. 

Others don't download at all.

In one recent case, Traffic Commissioner Nick Jones dealt with a PSV operator who hadn't downloaded the vehicle unit since 27 May 2015. 

They'd exceeded the legal requirement by 548 days.

The operator also hadn't downloaded data from a driver card. When the driver was stopped by North Wales Police, DVSA found that he'd failed to take sufficient rest on four separate occasions. 

If you're running digital vehicles, review your procedures against the legal requirements here.